How To Use ffmpeg to merge audio_only.webm with video_only.webm

[carlarogers]

This is how this came to me. One file is audio-only.webm and he other is video-only.webm

Is there a way to use ffmpeg to make a single webm file with both the audio and video playing together?

[LigH.de]

Probably yes, via mapping of streams, but the order of the command line parameters will be most important.

This StackOverflow article seems to document it verbosely.

Do the stream analysis as described there, and please report which command line worked for you, if you were successful.

[ProWo]

Try my clever FFmpeg-GUI. You can mux them to mp4 or mkv.
Load your video.webm first, select multiplex, the video source is already loaded, select your audio.webm as audio source, select what you wish as target file name, select mp4 or mkv as container, click Multiplex. Done.

[jagabo]

This should work:

ffmpeg -i video.webm -i audio.webm -c copy output.webm